US 2006/0154598 discloses a method of configuring and operating a radio system employing the ZigBee radio standard. The method enables a group of radio devices which are logically linked to another radio device to respond with low latency to a message. The method comprises a group identifier being generated and issued to logically linked devices, details of which are provided in a pre-installed binding table. In operation, a radio message from a device which is logically linked to another one is received by a device coordinator which then broadcasts the message with the generated group identifier. Only those devices that have previously received a matching group identifier respond to the broadcast message. Since broadcasts are not acknowledged, a rapid system response is achieved.